Breakaway couplings of various types are known. Typically, couplings employ detents, shear pins, and springs to fasten the nipple and coupler together. U.S. Pat. No. 4,906,031 to Vyse employs a garter spring situated in a groove in the female member which then engages an arcuate surface on the male member when the male and female members are coupled together. Specifically, Vyse discloses a garter spring located on surfaces which are designed so as to maintain the shape of the garter spring. The garter spring of Vyse is cylindrical. U.S. Pat. No. 4,896,688 to Richards et al. discloses a spring situated in a groove on the male member which expands radially outwardly to engage the female member and secure the male and female members together. U.S. Pat. No. 4,682,795 to Rabushka et al. discloses a spring which wraps around the male and female members to fasten them together under the tension of the spring.
The novelty of the present invention is directed toward the use of a canted coil spring which resides in the female half, otherwise referred to herein as the coupler, and which engages and maintains the nipple in position when the coupler and the nipple are joined. Additionally, the present invention also employs a check valve within the nipple which includes a bleed port. Similarly, with respect to the coupler, a vent passageway is also supplied which allows gas under pressure to escape to the exterior of the breakaway coupling. The venting means of the coupler is necessary because the seals leak. The venting means of the check valve is necessary to permit the breakaway coupling and downstream hose to vent so that the nozzle may be disconnected from the vehicle when the fueling operation has been completed.